Various mechanical excavations systems may be used in a variety of excavating applications. For example, tunnel boring machines (“TBMs”) are commonly used in tunnel excavation. TBMs can bore through any number of materials, from hard rock to sand and can produce tunnels of different diameters. A typical TBM includes a rotating cutterhead that chips, cracks, scrapes, rips, and otherwise removes material during rotation. More specifically, TBMs may include ripping and scraping tools that may engage material as the cutterhead rotates. Furthermore, as the cutterhead removes material, the TBM may advance the cutterhead to facilitate further engagement of the cutterhead with material. Likewise, the TBM may press the cutterhead against material to provide engagement of the cutterhead with the material.
After the material fails due to engagement with the cutterhead as the cutterhead rotates, the failed material is collected and removed as debris. As the ripping and scraping tools engage and fail the material, however, the tools commonly experience wear and/or breakage, which leads to failure or reduced effectiveness of the tools. Moreover, failure or reduced effectiveness of the tools may necessitate removal and replacement thereof. As such, the useful life of the tools may be a significant limitation in the operating efficiency of mechanical excavation systems using these tools, such as the TBMs.
For example, while the tools may be replaced, the mechanical excavation systems may require stoppage to change out the tools. Moreover, such stoppage may last several hours, as technicians remove, replace, and/or repair the tools. This time- and effort-intensive repair activity reduces the overall efficiency or rate of mechanical excavation systems using the disc cutters.
Therefore, manufacturers and users of mechanical excavation systems continue to seek improved ripping and scraping tools as well as manufacturing techniques therefor.